The present invention relates to beds and other patient-supporting devices, and particularly to a deck for supporting a mattress on a bed or other patient-supporting device. More particularly, the present invention relates to a step deck for a hospital bed, a patient-care bed, a stretcher, a gurney, or other devices having a support surface for supporting a person in a generally supine position. The deck or "step deck" as it is referred to herein has a central, longitudinally extending deck portion and raised or elevated longitudinally extending upper deck portions along the sides. The step deck carries a mattress or pad and in some embodiments the step deck can be configured to articulate so that the step deck assumes a variety of positions.
Beds and examination tables having articulating decks to adjust the position of the person on the support surfaces thereof are known in the art. See, for example, U.S. Pat. Nos. 5,077,843 to Foster L. Dale et al., 5,157,800 to Borders, 5,129,177 to Celestina et al., 4,862,529 to Peck, and 4,751,754 to Baily et al., all of which are assigned to the assignee of the present invention, and U.S. Pat. Nos. 3,281,141 to Smiley et al., 5,279,010 to Ferrand et al., 4,183,109 to Howell, 4,411,035 to Fenwick, and 3,220,022 to Nelson, as well as German publication No. 716981. Each of these references discloses a bed or an examination table having a top surface that articulates to adjust the position of the person on the surface. See also U.S. Pat. No. 5,715,548, the specification of which is herein incorporated by reference.
According to the present invention, a support assembly such as a bed, a stretcher, a gurney, or the like, is provided for supporting a person in a supine or generally supine position. The support assembly comprises a deck having an upper deck portion and a central, longitudinal recess in the upper deck portion. The recess is defined by a lower deck portion and walls connecting the lower and upper deck portions.
The support assembly can also include a mattress that rests on the deck. The mattress includes a generally planar, upwardly-facing support surface, side portions resting on the upper deck portions, and a central portion or projection extending downwardly into the recess. If desired, the central portion of the mattress can conform to the shape of the deck to nest in the recess and engage at least a portion of the side wall of the deck so that the central portion cooperates with the side walls to minimize lateral and longitudinal sliding of the mattress relative to the bed.
In preferred embodiments, the bed includes a base frame, an intermediate frame coupled to the base frame, a weigh frame coupled to the intermediate frame, and an articulating deck coupled to the weigh frame. The articulating deck has longitudinally spaced head, seat, thigh, and foot sections. The head, thigh, and foot sections are movable relative to each other and are movable relative to the seat section which is fixed relative to the weigh frame. The head, thigh, and foot sections are infinitely adjustable to allow the bed to attain any desired position within the range of movement of the head, thigh, and foot sections, thus accommodating changes of position of a person on the bed. The illustrative articulating deck can provide a planar, horizontal sleeping surface, a planar sleeping surface that is tilted toward either the head end of the bed or the foot end of the bed, and a non-planar chair-shaped seating surface, in addition to the intermediate positions therebetween.
The bed can include a mechanism for raising and lowering the articulating deck and the sleeping surface between a low position and a raised position relative to the base of the bed. In addition, the bed can also include mechanisms for independently raising and lowering each of the head section, the thigh section, and the foot section so that the bed can assume many positions.
A pair of side rails can be provided on each side of the bed. Each pair of side rails includes a head section side rail that is movable with the pivoting head section of the deck and a body section side rail that is mounted to the weigh frame. Each side rail has a top and a bottom and is preferably maintained in a generally vertical orientation adjacent to the sides of the bed.
The side rails are each movable between a downward tucked position and an upward patient-restraining position restraining the movement of a person on the sleeping surface past the sides of the sleeping surface. When in the patient-restraining position, the bottoms of the side rails are positioned to lie above the upper deck side portions and the side rails advantageously abut sides of the mattress. This feature reduces the likelihood that a patient may be trapped between the mattress and the side rails. When in the tucked position, the tops of the side rails are positioned to lie beneath the upper deck side portions in a niche defined by the upper deck side portions and the side walls connecting the lower deck to the upper deck side portions.
It is also an object of the present invention to provide a bed for supporting a person, the bed being convertible between a sitting position and a bed position. The bed includes a frame and an articulating deck on the frame. The deck includes longitudinally spaced head, seat, and foot sections movable relative to each other to accommodate changes of the position of the bed. The deck sections have longitudinally extending upper side deck portions. The deck further includes a central, longitudinally extending recess defined by a lower deck portion and walls connecting the upper and lower deck portions. The bed further includes a mattress resting on the articulating deck. The mattress has a planar, upwardly-facing support surface, side portions resting on the upper deck portions, and a central projection extending downwardly into the recess.
In preferred embodiments of the bed, the step deck includes a head end and a foot end, and the head and foot ends of the deck are provided with upper deck end portions and walls connecting the lower deck to the upper deck end portions. In addition, the sleeping surface is generally planar and the projection is centrally located beneath the sleeping surface to form a thick centrally located portion of the mattress. The varied thickness of the mattress provides the mattress with "zones" including a thick body-support zone adjacent to the projection and a thin zone in areas away from the projection. The portion of the mattress adjacent to the upper deck portions form a thin perimetral zone engaging the upper deck portion.
The mattress may be provided in more than one piece, for example, a first mattress piece could fit into the recess and a second mattress piece could engage the upper deck portion and surround the first mattress piece, or a first mattress piece could fit into the recess and a second mattress piece could cover the first mattress piece and engage the upper deck portion. However, a one-piece mattress including both the body-support zone and the perimetral zone is presently preferred.
The mattress additionally includes mattress sides connecting the sleeping surface and the bottom surface of the mattress. The step deck is configured so that the mattress sides are exposed, rather than being partially covered by a frame or an upstanding wall of a deck. Exposure of the mattress sides above the step deck maximizes the access of the caregiver to the mattress.
Additionally, the mattress in accordance with the present invention is thinner along the perimetral zone of the mattress where the mattress engages the upper deck portions of the articulating deck, providing "rammed edges" that increase firmness experienced by the person around the edges of the mattress. This increased firmness is advantageous when the person enters and exits the bed along the sides of the bed. In addition, the mattress is thicker in the body-support zone that carries a greater portion of the weight of the person for most of the time that the person is carried by the bed, for example toward the center of the head, seat, and thigh portions of the mattress, maximizing the comfort of the person.
The mattress includes a head mattress portion, a seat mattress portion, a thigh mattress portion, and a foot mattress portion. Each named mattress portion is associated respectively with the head, seat, thighs, and feet of the person resting on the sleeping surface of the bed as well as with the underlying head, seat, thigh, and foot sections of the deck.
The step deck and the mattress configured for use with the step deck can be used independently of the bed and the articulating deck. For example, the step deck can be provided for a stretcher having a frame, a step deck mounted to the frame, the step deck having longitudinal upper side portions, and a mattress having a generally planar sleeping surface and a bottom surface including a downwardly extending projection. In the same manner, a step deck and associated mattress could be provided for a gurney. Such a gurney would be similar to the illustrative stretcher described above except that the frame would include wheels so that the gurney could be transported by rolling it from place to place.
Though there are many potential variations of step deck shapes and corresponding mattress shapes and numbers and types of mattress pieces that could be devised, any step deck having an upper deck portion and a recess defined by a bottom deck portion and walls connecting the bottom and the upper deck portions would achieve the desired results. Likewise, any mattress or combination of mattress pieces that provide a bottom surface generally conforming to the shape of the step deck would achieve the desired results.
It is still another object of the present invention to provide a bed with cooperating step deck and side rail features. The bed has a head end, a foot end, and two opposing sides, and comprises a frame and a deck carried by the frame. The deck includes an upper deck portion and a central, longitudinally extending recess in the upper deck portion. The recess is defined by a lower deck portion and walls connecting the lower and upper deck portions. The bed further includes a side rail coupled to the bed below the upper deck portion and positionable in a patient-restraining position above the upper deck portion and in a tucked position below the upper deck portion.
The side rails are mounted to the articulating deck and to the weigh frame for movement between the patient-restraining position and the tucked position. The mounting mechanism causes the side rails to rotate downwardly when released from the patient-restraining position, first rotating outwardly and downwardly and then inwardly and downwardly to the tucked position which is beneath the patient-restraining position. The rotating action of the mounting mechanism positions the tucked side rails and the mounting mechanism so that clearance between the side rails and the floor is maximized. The positioning of the side rails beneath the deck when in the tucked position also helps caregivers to improve the positioning of the person when moving the person on and off of bed.
As described above, the mattress of the bed includes a thick mattress portion and a thin mattress portion engaging the upper deck portions along the sides of the deck. As a result, the upper deck side portions are typically farther from the floor than the bottom of the step deck. This allows the side rails to be mounted farther from the floor than would be found on a bed without the step deck. This positioning provides additional obstruction-free space between the tucked side rails and the floor for access under the deck, for example, for equipment such as a C-arm having portions above and below the deck.
In addition, when the side rails are in the patient-restraining position, the distance between the bottom of each side rail and the top of each upper deck portion is minimized. The side rails are positioned above the deck and can abut the side of the mattress. A bed having a conventional deck, a conventional mattress of uniform thickness, and side rails mounted at a height relative to the sleeping surface similar to that found in the bed of the present invention would also have the bottoms of the side rails further from the conventional deck than is found in the present invention, resulting in a larger gap between the bottom of the side rail and the conventional deck. Use of the step deck provides upper deck portions which are positioned to lie closer to the bottoms of the side rails, thus minimizing the gap between the deck and the bottoms of the side rails and minimizing the possibility of a person sliding through the gap.
It is a further object of the present invention to provide a bed having a unique combination of a step deck and a pivoting and contracting foot section. The bed has a head end, a foot end, and two opposing sides, and is convertible between a sitting position and a bed position. The bed includes a frame and a deck carried by the frame. The deck has an upper deck portion and a central, longitudinal recess in the upper deck portion, the recess being defined by a lower deck portion and walls connecting the lower and the upper deck portions. The deck further includes a foot section that is pivotably coupled to the deck. The deck foot section contracts and expands between a first length and a second length, the first length being greater than the second length.
The foot section has a head end toward the head of the bed and a foot end toward the foot of the bed. The head end of the foot section is pivotably coupled to the upper deck portion. The foot section can include a pivoting member pivotably coupled to the upper deck end portion for movement about a pivot axis and a sliding contracting member slidably coupled to the pivoting member. The contracting member can be configured to translate radially inwardly and radially outwardly relative to the pivot axis.
The step deck includes an upper deck end portion positioned to lie longitudinally between the thigh section and the foot section, and spanning the width of the bed between the upper deck side portions. The upper deck portions, including the upper deck end portion, are positioned to lie in a first horizontal plane that is above a second horizontal plane defined by the lower deck. The vertical distance between the first and second horizontal planes is the vertical offset.
The pivoting member of the foot section is mounted to the upper deck end portion rather than to the lower deck. Consequently, the foot section, when in the down position, can be longer by an amount equal to the vertical offset than it could be if there were no step deck, and the foot section were instead connected to the lower deck. Thus, for the foot section to clear the floor when the pivoting member of the foot section pivots from the up position to the down position, the contracting member of the foot section can contract a lesser amount than would be required if there were no step deck.
The mattress carried on the step deck includes a foot portion adjacent to the foot section of the bed. The foot portion of the mattress can be configured to shorten in conjunction with the contraction of the foot section. Also, the foot portion of the mattress can automatically become thinner to maintain an appropriately sized seat area as the foot section pivots downwardly. To achieve this result, the foot portion of the mattress can be inflatable and can be inflated when the foot section is in the up position. When the foot portion of the mattress is inflated, the foot portion cooperates with the other mattress portions to provide a generally planar sleeping surface. The foot portion of the mattress is automatically deflatable and inflatable and automatically inflates and deflates as the foot section of the deck pivots between the up position and the down position.
Additional objects, features, and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiment exemplifying the best mode of carrying out the invention as presently perceived.